There are known panels with conductive cores which are used for example to supply lamps inserted in these panels. These panels comprise two layers of conductive material, generally a metallic sheet and three layers of insulating material so as to sandwich the conductive layers. The elements which are inserted in these panels comprise, either a single pin with two contact regions at two different heights corresponding to the depth of the conductive layers when the element is inserted to the hilt, or to separate pins each with a contact region of suitable height.
One application relates to use in stands at expositions.
Thus in this case, the exhibitors must display products by means of directed illumination and this from reduced numbers of electrical supply outlets. The panels with conductive cores require only one supply for an entire surface or even several surfaces in parallel or series.
Such panels have numerous other advantages, among which is the opportunity to change the position of one of the points of illumination or any other electrical component, the modification of the type of one of these components or again the addition or substraction of one of these components.
It is also known that such panels can be provided with coverings of different natures and different colors to harmonize these panels with the surroundings.
Another advantage of these panels is their light weight, which permits them to be handled and imparts great freedom to the arrangements.
These panels can also be cut and shaped, thus giving free rein to creativity.
The present applicant has also proposed conductive frames permitting associating such panels in series or rendering them portable.
There are known numerous processes for the production of such panels, disclosed in patent application WO 94/03947.
As a result of extensive research, the present invention provides a panel thus obtained, which overcome the following drawbacks.
Thus, if the panels presently produced operate and give complete satisfaction, there nevertheless remain imperfections over the long term concerning the contact.
In the course of time, an element, for example a single pin, inserted in the panel by means of its pin, becomes non-conductive. It suffices to reposition it immediately adjacently so that it will again operate. It will be noted that the pin serves both as a contact and as a conductor but also has a mechanical support for the element to which it is connected.
It is noted more particularly that the pins of complete circular cross-section can rotate in the panel, which, upon introduction, enlarges the penetration hole whilst permitting air to enter interrupting contact with the pin, the passage of current then forms aluminum oxide, forming an aluminate which is an insulator. This is facilitated by the fact that the pin is often touched with the fingers, thereby imparting supplemental moisture which accelerates the oxidation process.
It is therefore of interest to be able to improve the pressure of the panel in the horizontal plane to limit the penetration of air.
A new pin has been proposed in a related application so as to improve the contact capability of said pins and the present invention provides a panel which overcomes the problem of degradation of the quality of contact in the course of time, by means of characteristics adapted to be used in industrial production.
As would be imagined, if the initial contact is of poor quality, there results heating which, in the thermally insulating foam, leads to a buildup of heat, which degrades the foam and simultaneously degrades the quality of the contact and so on until the electrical contact ceases by loss of contact pressure.